Dental crown-slitter.



No. 734,865. PATENTED JULY 2a, 1903.

1 G. K. HEIST.

DENTAL, GROWN SLITTBR.

APPLICATION FILED MAY 21, 1903.

' .170 MODEL.

Inventor Withesses I q I 6/19/51 /:,A Q I Attorney:

nave asei Patented July 28, 1903.

"FFICE.

PATENT GEORGE KENTON HEIST, OF WINCHESTER, VIRGINTA.

DENTAL CROWN-SLITTER.

sPEoIFIcATIofi forming part of Letters Patent No. 734,865, dated Jilly 28, 1903.

Application filed lllay 21,1903. Serial no. 158.153. (N model.)

1'0 all whom it may concern.- Be it known that I, GEORGE KENTON HEIST, a citizen of the United States, residing at Winchester, in the county of Frederick and State of Virginia, have invented certain new and usefullmprovements in Dental Crown-Slitters; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable othersskilled in the art to which it appertains to make and use the same.

My invention is an improved implement for slitting a gold or other crown or cap piece of a tooth for the purpose of enabling the crown to be removed from the tooth without marring the crown; and it consists in the peculiar construction and combination of devices herein after described and claimed.

In the accompanying drawings, Figure 1 is a side elevation of my improved implement, showing the knife and the operatingbar thereof in their initial position in full lines Fig. 2 is a detail sectional view on a larger scale, showing the connection between the-knife and the slide-bar which carries it and also showing the connection between the cushion and the arm of the relatively fixed bar. Fig. 3 is a detail sectional view taken on the line a a of Fig. 1.

.In the embodiment of my invention I provide a relatively fixed bar 1 of suitable length,

at the outer end of which is a head 2, which may be made of wood or any other suitable material, and which is adapted to rest in the palm of the hand of the operator. The inner end of the said bar is curved at an angle thereto, as at 3, and its extreme inner end forms an arm 4, which is at right angles to the said bar. Said arm is provided near its outer end with an opening 5 and is provided on its outer side at a suitable distance from the said opening with a socket 6, with which socket communicates an opening 7, that extends through the said arm. The said bar 1 is preferably semicylindrical in shape, with its flat side coincident with its curved portion 3 and arm 4:. r

Aslide-bar 8 operates on the bar 1, is of suitable length, and is connected to the said bar 1 by a cylindrical band 9 and a yoke 10, the

latter being provided with laterally-extend ing arms 11, which are preferably at right angles to the arm 4. The inner end of the said slide-bar 8 is obliquely disposed and curved, as at 12, to conform to the curved portion 3 of the bar 1, and is further provided with an arm 13, which is parallel with the arm 4. of bar 1 and is adapted to close snugly against the same. The bar 8 is preferably semicylindrical in shape, and its flat side is opposed to that of the bar 1.

The knife 14 is preferably of the form shown and comprises a stem 15, which tapers outwardly, and a blade 16, which projects at right angles from the said stem at its outer end, the inner edge of the said blade being its cutting edge and the sides of said blade being beveled and converging toward its cutting edge. end a shoulder 17, which bears against one side of the arm 13, and a threaded portion 18, which projects through an openingin the said arm 13. A nut 19 is screwed on the said threaded portion and bears against the outer side of the arm 13 and coacts with the said threaded portion of the stem to clamp the latter firmly to said arm.

On the outer side of the arm 4 of the relatively fixed bar 1 is a cushion 20, which is made of rubber or gutta-percha and which is pressed into the socket 6 and opening 7. This cushion is adapted to conform to the shape of the crown of the tooth to which it is applied and the crown which is to be slit. Normally the arm 13 of the slide-bar 8 is closed against the arm 4 of the relatively fixed bar 1, so that the implement may he applied to the tooth to have the cushion bearing against the crown of the tooth and the blade of the knife on the side thereof in position to slit the crown. The operator by pressing his fingers against the arms 11 of yoke draws the bar 8 upwardly or downwardly, thereby causing theblade to pass acrossthe side of the cap of the crown and to slit the same, as will be understood. The crown is not marred materially by being thus slit, and it may be then readily removed from the tooth without injuring the crown.

From the foregoing description, taken in connection with the accompanyingdrawings,

The said stem has at its inner a slide-bar on the relatively fixed bar having means at its outer end whereby it may be moved longitudinally, and having at its inner end a cutter adapted to coact with the arm of'the relatively fixed bar, substantially as described.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

G. KENTON HEIST.

Witnesses:

BENJ. G. CoWL, E. F. OAVERLY. 

